Vacuum pump



FIG. 1 is a side view of a vacuum pump, showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a side view opposite to the side view shown in FIG. 1;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top, side and front perspective view thereof.

The areas shown in broken lines show environmental structure only and form no part of the claimed design. 

The ornamental design for a vacuum pump, as shown and described. 